In order to add new strategies you need to edit the JSON file(s) in the config folder.
Add the information at the top of the relevant array (most likely strategiesV4) and then also update the graft information so that you can copy data from a previous subgraph instead of reloading from scratch. The block should be one before the block in which the earliest of the new strategies you are adding was deployed, and blockPlusOne will be the block in which that earliest new strategy was deployed. Doing this ensures that the handleOnce function in the mappings file will run again and that new sources will be created using the templates.